Polyeptoids are a promising class of polypeptide mimetic biopolymers based on N-substituted glycine backbones. Because of the high designability of their side chains, polypeptoids have a wide range of applications in surface antifouling, biosensing, drug delivery, and stimuli-responsive materials. To better control the structures and properties of polypeptoids, it is necessary to understand different methods for polypeptoid synthesis. This review paper summarized and discussed the main synthesis methods of polypeptoids: the solid-phase submonomer synthesis method, ring-opening polymerization method and Ugi reaction method.

Carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) composite nanofiber membranes were prepared by electrostatic spinning, using CMC and PVA as raw materials and glutaraldehyde as a cross-linking agent. The structure, morphology, thermal stability, and filtration performance of CMC/PVA nanofiber membranes were characterized by advanced instrumental analysis methods such as scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, ultraviolet analysis, and energy spectrum analysis. The results show that the average fiber diameter decreases from 381 nm to 183 nm when the spinning voltage is 23 KV and the jet speed is 2 µL/min. The obtained fiber has the smallest particle size and the most uniform distribution. Infrared spectroscopy analysis confirms that the adsorption behavior of nanofiber membranes on Cu²⁺ and Cr⁶⁺ is chemical adsorption. The retention rates of CMC/PVA nanofiber membranes for Cu²⁺ and Cr⁶⁺ reached 97.2% and 98.8%, respectively. The adsorption capacities of Cu²⁺ and Cr⁶⁺ were 26.34 and 28.93 mg·g⁻¹, respectively. The adsorption of heavy metal ions by nanofiber membranes can be explained by the pseudo-second-order kinetic mechanism of the chemisorption process and the Langmuir isotherm model.

A safe, efficient and stable antifreeze agent, antifreeze protein mimic peptoid, that is targeted to use in cryopreservation is reported.